1. Field of the Invention
The present invention relates to a finger operable pump that is capable of dispensing liquid from a container in a substantially continuous manner.
Finger operable pumps are frequently installed on portable, non-pressurized containers for intermittent use to dispense consumer liquid products such as window and all-purpose cleaners, polishes, lubricants, pesticides, room deoderizers and personal products such as hair setting lotions, hair spray, antiperspirants and perfumes. The containers are adapted to be hand-held and the pump is adapted to be operated by one of the user's fingers on the same hand.
These pumps and the containers on which they are installed are often intended to be thrown away when the contents of the container have been exhausted. Therefore, the pumps should be mechanically simple and have components that are made from inexpensive materials. These components should further be easy to assemble in order to make the pump and container package economically feasible.
Additionally, it is desirable to dispense some liquid products in a substantially continuous manner. For example, it is desirable to apply hair setting lotion and hair spray to the hair in a continuous mist. Similarly, it is desirable to apply certain polishes such as furniture polish in a continuous mist.
2. Description of the Prior Art
Finger operable pumps used with disposable containers of liquid products are presently known.
However, certain prior finger operable pumps which are capable of providing a continuous product discharge are mechanically complicated or difficult to operate. For example, U.S. Pat. No. 3,741,065 (Malone) discloses a liquid pump that employs a separate air pump to develop air pressure in a head space above liquid in a container. When dispensing is desired, a separate actuator button is pressed to allow release of the product.
U.S. Pats. Nos. 3,733,010 (Riccio) and 3,733,031 (Marand) disclose pumps with pistons which develop an air pressure head during a piston down stroke. The air pressure is suddenly released at the end of this down stroke by tripping a release valve. The resulting spurt of high pressure air is conducted through a venturi to aspirate fluid stored in the container.
U.S. Pat. No. 3,211,346 (Meshberg) discloses an aerosol package in combination with a piston pump designed to effect a spray discharge. Liquid is fed to a chamber by aerosol pressure and is then forced by a mechanical piston through a discharge nozzle.
Examples of other liquid dispensing pumps are disclosed in U.S. Pat. Nos. 3,452,905 (Miscallef); 3,255,933 (Martin); 3,162,372 (Viard); and 3,161,329 (Fedit et al).